This research will evaluate, through an observational study, whether pain management methods of physicians are associated with increased risks of dysfunctional chronic pain (DCP) in patients. DCP is defined as severe and persistent pain with significant acitvity limitation. Associated manifestations of DCP include: psychological impairment, frequent use of health care and pain medications, interference with social role performance and preoccup0ation with the pain experience. In order to establish a methodologic basis for investigation of health care determinants of DCP risks, this research will: (1) Validate the West Haven-Yale Multidimensional Pain Inventory (MPI) classification of DCP in primary care samples of patients with back pain and headache; and (2) Investigate the prevalence, incidence, and duration of DCP, and patient characteristics asssociated with DCP risks. The independent variables of primary interest are measures of physician pain management methods including: incomplete examination and history taking; prescribing pain scheduled analgesia; prescribing excessive and pain scheduled bed rest; profiding an ambiguous or threatening explanation of the causes of pain; prescribing non-conservative treatment on the basis of lack of response to conservative treatments; high use of specialty and testing services; and low use of behavioral and psychological interventions directed at modulation of pain perceptions, appraisals and behaviors. The primary response variables will be measures of DCP prevalence, one year cumulative incidence, and the probability of DCP continuing one year after baseline. This research will: Assess the extent of systematic physician variation in use of pain management methods hypothesized to increase DCP risk. That is, are there "high risk" and "low risk" styles of managing pain conditions that can be reliably observed among primary care physicians? Investigate whether patients with DCP cluster within certain primary care practices. That is, do primary care practice panels vary significantly in the prevalence3, incidince or duration of DCP? Test whether patients exposed to high risk pain management methods have increased risks of DCP. Test whether physicians who characteristically employ high risk pain management methods have higher DCP risks among their patients than primary care physicians who use low risk methods, after adjusting for case mix. These objectives will be accomplished by the following methods: Sixty full time primary care physicians will be selected at random from the 120 Group Health Cooperative (GHC) physicians in the Greater Seattle area. Patients seeking care for back pain (n=1200) or headache (n=1200) from these 60 physicians will be interviewed by telephone subsequent to their index visit to assess DCP status and physician methods of treating their pain condition. All subjects will be re-inbterviewed one year later to measure onset and duration of DCP. Additional patient data will be obtained from medical records and automated utilization and pharmacy data of GHC. The pracitce style of the 60 physicians will be characterized using data from the 20 back pain and 20 headache patients per practice, and by automated data from their entire panel.